466 
Journal of Agricultural Research 
Vol. XXI, No. 7 
Table I .—Effect of growing Irish Cobbler potatoes at different temperatures in soil 
inoculated with a pure culture of Corticium vagum 
EXPERIMENT i 
/O /S ?0 PS GO 
C£A/T/G/P/}/?f 
Fig. i.—R elation of soil temperature to the severity and to the distribution of the injury on potato stem 
caused by Corticium vagum (experiment i). 
All control plants remained entirely free from lesions except those in 
one can in each of the two tanks held at the two lower temperatures. 
These plants showed definite brown cankers accompanied by the char¬ 
acteristic mycelium of Corticium vagum . The lesions, however, were 
relatively slight and indicated a possible late infection. The accidental 
inoculation of the soil in these control pots may have resulted in one of 
three ways: (i) From imperfect surface sterilization of tubers used for 
